Apparatus for recording or reproducing sound on films



Oct. 2,1934. A. s. JOANNIDES APPARATUS FOR RECORDING 0R REPRODUCING SOUND ON FILMS Filed Nov. 2, 1933 ALEXANDRE GEORGES JOANNIDES INVENTOR ATTORNEYS Patented Oct. 2, 1934 UNITE STATES APPARATUS FOR RECORDING OR REPRO- DUCING SOUND ON FILMS Alexandre Georges Joannides, Paris, France, as-

signor to Societe Pour LExploitation Des Brevets, A. G. 1., Paris, France 1 Application November '2, 1933, Serial No. 696,33 In France December 17, 1932 a cl i s. (01. 179- -100.s)

This invention relates to apparatus for recording or reproducing sound. on films, particularly cinematograph films, and especially to apparatus of the kind comprising an optical system consisting of a system ofreducing lenses carried by a tubular casing,"the casing having a slot-like aperture, situated usually at the upper end of the casing, through which a pencil of light rays from a convenient source can be directed on to the film. Alternatively, the slot-like aperture may be omitted, and a lamp employed having a rectilinear filament. In such a case the lamp socket is either formed integral with the tubular casing or is secured firmly in position thereon. It is the present practice in such apparatus to mount the optical system so that it can be turned about its axis by hand to adjust the aperture or source of light relatively to the film and to lock the optical system in its adjusted position by suitable securing screws or nuts.

It is found in practice that this method of adjusting the optical system is inaccurate, and the chief object of the invention is to provide means whereby such adjustment may be effected in a simple and accurate manner.

Referring to the drawing:-

Figure 1 is a perspective View of an optical system mounted within a suitable supporting bracket and incorporating the present invention.

Figure 2 is a vertical section to an enlarged scale showing the eccentric in the position it occupies when in use.

Figure 3 is a fragmentary View to an enlarged scale showing the inner end of the eccentric and its associated slot.

Figure 4 is a vertical section to an enlarged scale showing the eccentric in the position it occupies when inserting or withdrawing the optical system from its supporting bracket.

In the construction illustrated the optical system is mounted within a supporting bracket 1, the optical system comprising a tubular casing 2 carrying a system of reducing lenses 3 at it lower end and provided at its upper end with a dia- I metrically arranged slot-like aperture 4 through which a pencil of light rays can pass downwardly through the casing and impinge on the film after passing through the system of reducing lenses.

The tubular casing 2 is rotatably mounted within the supporting bracket 1, and is adapted to be locked in any position into which it may be adjusted by means of securing screws 5 located within the supporting bracket. The tubular casing may have a peripheral flange or shoulder 6 which is adapted to contact with the upper surface of the supporting bracket and thereby 1ocate the tubular casing therein in' an axial direction. The supporting bracket is provided with a protuberance or boss '7- which is bored for the reception of the shank 8 of an eccentric 9, the shank having an enlarged head 10 provided with a saw cut in its extremity for receiving a screwdriver 'or other instrument with which the eccentric may be turned. Alternatively, the shank 8 may have a milled or other head or projection wherebyit may be turned by hand. 'The eccentric is adapted to-'-pass through and engage'the walls of a slot 11 in the wall of the tubular casing, the slot being preferably of inverted keyhole shape as shown in Figure 3. In use, the eccentric is adapted to engage the walls of the narrow part 12 of the key-hole slot as in Figure 2. In order to prevent the accidental removal of the eccentric from the narrow part of the key-hole slot the end of the eccentric is preferably provided with an enlarged head 13 which is of a larger diameter than the width of the narrow part of the slot. In order that the eccentric can be inserted initially into the narrow part of the key-hole slot, or removed therefrom, the tubular casing is raised within the supporting bracket into a position shown by Figure 4, in which position the enlarged part 14 of the keyhole slot is disposed directly opposite the enlarged head 13 of the eccentric, in which position the eccentric can be readily inserted or withdrawn.

In operation, rotation of the eccentric by means of a screw-driver or other instrument or by hand will cause the eccentric to bear against the adjacent edge of the narrow part of the keyhole slot, and thereby cause the tubular casing to be turned axially within its supporting bracket, thereby adjusting the slot-like aperture 4 angularly. After adjustment the tubular casing may be locked in its adjusted position by means of the securing screws in the supporting bracket, which cause the walls of the bracket to be drawn together and to grip the outer surface of the tubular casing.

What I claim and desire to secure by Letters Patent of the United States is:-

1. In apparatus for recording or reproducing sound on film, a light source, an optical system disclosed between said light source and said film for directing a beam of light from said light source on to said film, said optical system comprising a tubular casing carrying a system of reducing lenses, a supporting bracket carrying said tubular casing and means for turning said tubular casing axially for adjusting the position of the beam of light relatively to said film, said means comprising an eccentric revolubly mounted in a bearing in said supporting bracket, said tubular casing being cut away to constitute .a slot for engagement by said eccentric, said slot being of key-hole shape.

2. In apparatus for recording or reproducing sound on film, a light source, an optical system disposed between said light source and said film for directing a beam of light from said light source on to said film, said optical system comprising a tubular casing carrying a system of reducing lenses, a supporting bracket carrying said tubular casing and means for turning said tubular casing axially for adjusting the position of the beam of light relatively to said film, said means comprising an eccentric revolubly mounted in a bearing in said supporting bracket, said tubular casing being cut away to constitute a slot for engagement by said eccentric, said slot comprising a narrow portion having its axis disposed parallel to the axis of said tubular casing and a circular portion of relatively large diameter communicating with said narrow portion, said eccentric having an enlarged head of greater diameter than the width of said narrow portion but smaller in diameter than the diameter of the enlarged portion of said slot for the purpose specified.

3. In apparatus for recording or reproducing sound on film, a light source, an optical system disposed between said light source and said film for directing a beam of light from said light source on to said film, said optical system comprising a tubular casing carrying a system of reducing lenses, a supporting bracket carrying said tubular casing within which bracket said tubular casing is turnable axially and also slidable vertically, a shoulder on said tubular casing for locating said tubular casing relatively to said vsupporting bracket, means for turning said tubular casing axially for adjusting the position of the beam of light relatively to said film, said means comprising an eccentric revolubly mounted in a bearing in said supporting bracket, said tubular casing being cut away opposite said eccentric to constitute a slot for engagement by said eccentric, said slot being of inverted keyhole shape and comprising a narrow portion with the edges of which the eccentric normally engages, and a circular portion of relatively large diameter communicating with said narrow portion, said eccentric having an enlarged head to prevent its withdrawal from the narrow portion of said slot, said enlarged head being of greater diameter than the narrow portion of said slot but of less diameter than the diameter of said slot portion of relatively large diameter to enable the eccentric to be withdrawn from said slot upon said tubular casing being raised into a position in which the part of said slot of relatively large diameter lies opposite the enlarged head of said eccentric.

ALEXANDRE GEORGES J OANNIDES. 

